Quote Originally Posted by Gwelenguchenkus
Really. That is definitely interesting that revenge was his main motive over saving the world. I can't think of a main character quite like that other than cloud.
He was certainly the only one in the Final Fantasy series to be like that. Cloud really wasn't a hero so much as an anti-hero. I'm thinking that was the intention due to the pervading dark themes of the game. Zack was more the hero than Cloud, really. He seemed to be a rather decent fellow from what we saw, breaking Cloud out of the Shin-Ra Mansion when he didn't really have to, and then running back to get Cloud on the bluff above Midgar instead of escaping on his own, getting killed in the process.

I believe that was the intent, and that the flashback scene in which Zack dies shows us one of the intended themes of the game: The hero was dead before the game even started, and things fell to an anti-hero to save the day.